diff --git a/parser/parser.mly b/parser/parser.mly
index 91ba563..540f422 100644
--- a/parser/parser.mly
+++ b/parser/parser.mly
@@ -24,7 +24,7 @@ open Ast
 %token DATE TIME TIMESTAMP
 %token <int> INTEGER 
 %token <float> FLOAT
-%token UNDERSCORE QUOTE COLON
+%token QUOTE COLON
 %token EOF
 %start main
 %type <query> main
@@ -61,7 +61,7 @@ literal :
   | general_literal { $1 }
 
 unsigned_literal:
-(*  | unsigned_numeric_literal { $1 }*)
+  | unsigned_numeric_literal { $1 }
   | general_literal { $1 }
 
 general_literal:
@@ -71,19 +71,17 @@ general_literal:
 character_string_literal:
   | QUOTE IDENT QUOTE { StringLiteral($2) }
 
-introducer:
-  | UNDERSCORE { }
 
 signed_numeric_literal:
-  | sign unsigned_numeric_literal {}
-  | unsigned_numeric_literal {}
+  | sign unsigned_numeric_literal { Signed($1,$2) }
+  | unsigned_numeric_literal { $1 }
 
 unsigned_numeric_literal :
   | exact_numeric_literal { $1 }
 
 exact_numeric_literal:
-  | FLOAT { }
-  | INTEGER {}
+  | FLOAT { FloatLiteral($1) }
+  | INTEGER { IntegerLiteral($1) }
 
 sign:
   | PLUS_SIGN { Plus }
@@ -190,10 +188,6 @@ nonparenthesized_value_expression_primary:
 
 unsigned_value_specification:
   | unsigned_literal { $1 }
-  (*| general_value_specification {}*)
-
-general_value_specification:
-  | {}
 
 (*********************************************)